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Pheromone Analyses

By pomm79, Aug 31 2015 10:12AM

From our preliminary pheromone analyses, we have concluded that pheromone-induced mortality of Dendroctonus brevicomis contributed substantially to the reduction of tree mortality caused by this bark beetle throughout the test area. Learn more about human pheromones | wordpress.com.

Suppression traps caught an estimated 405,000 D. brevicomis while pheromone survey traps caught an estimated 189,000 beetles during the same period (table 22.6). Tree mortality declined from 227.1 1 23.6 trees immediately before the test (i.e., 1969-70 overwintering infested trees) to 738 trees killed during the suppression. The high catch on survey traps relative to the low number of infested trees indicates that these traps actually played an important role in population suppression.

1) Total population produced by the 1969-70 overwintering generation and/by all subsequent generations up to, and including, emergence and attack by the 1970- 71 overwintering generation.

2) Community structure within trees infested by D. brevicomis for each generation.

3) Distribution of D. brevicomis and its natural enemies, and trees killed by D. brevicomis through the entire evaluation period.

4) Survey and pheromone suppression trap catch in relation to trees killed by D. brevicomis and to vegetative and physiographic characteristics of the trap site.

The approach and many of the pheromone techniques described in this case history are applicable} to other bark beetle species where population suppression with attractant pheromones is desired. Regardless of the speciﬁc technique used, i.e., ‘trap- out’, ‘baited tree’, or ‘interruption’, intensive evaluation of the treatment effects over large areas will be necessary. Methods of population and damage assessment must be available to make these evaluations of efficacy. Such evaluations are difficult and costly, and require the efforts of many individuals with a diversity of skills. Learn more about http://pheromones-work.weebly.com/

Pheromone Fixture

We are repeating (l97__l—74) this ‘trap-out’ technique, at McCloud Flats, Siskiyou County, California, together with full population evaluation to determine: 1) the effectiveness of the technique under population levels 10 times that occurring at Bass Lake; 2) how the technique can be modified to be effective over larger ar- eas; and 3) how to improve and hopefully simplify the population evaluation methods. We envision that future efforts leading to the operational use of the ‘trap-out’ method for D. brevicomis will include the development of a model(s) to assist in determining the combination of treatment variables that should be applied to reduce a population of known size. Check out pheromones for women 2017 | http://thongchaimedical.org. The model(s) will also provide prescriptions appropriate to speciﬁc pest situations, e.g., a small, high-value recreation area with a moderate pest population or a large, low-value area with a high population. The development of such models will be an iterative process wherein data from large- scale field tests and population studies of D. brevicomis will be used to predict pest abundance, given specific manipulations. As more data from field tests become available, the specific model can be tested and refined.